What's with the trend of casting Idris Elba in every part of every film these days?

The trend is that Elba is a black actor. He also happens to be a good actor. So people get to feel not racist when they hypothetically cast black actors as white characters. Then other people comment and say "I could live with this" "this would be awesome" "maybe not my first choice, but I can see it." So now we get to all sound not racist together!